Remnants of an old bank adorn this station's brick wall.

Several cannonballs of mysterious origins decorate two buildings in Stortoget's main square.

An abstract representation of weather in Sweden.

A miniature model of the iconic Stockholm department store.

Hidden in plain sight, Sweden's official ordnance datum is now abandoned.

There are hidden patterns on the subway seats of some Stockholm metro cars.

Small Easter eggs are hidden in the ventilation holes of the city's newest trains.

An entire shopping mall and industrial terrain named for the time the king of Sweden's car went into a ditch.

A miniature statue of a beloved character from children's literature.

These whimsical rabbit figures are not as innocent as they might look.

Inside this church, a monument honors the first burial site of the famed philosopher.

A large portion of this navigable canal runs under Paris's famed boulevards.

Notorious artist squat renovated into legal studios.

Executions were once held near this beautiful 18th-century fountain.

This small, ingenious cannon once helped regulate Parisian life.

The spiral staircase hidden inside this giant Parisian column was likely built for Catherine de Medici's astrologer.

With a history of slaughter, feast, and famine, remnants of the pork industry decorate this area--even its church.

This bridge was constructed from the rubble of the infamous Bastille.

A Parisian cemetery where the elite and artistic are interred beneath an eccentric collection of tombs.

A series of abstract, silly sculptures represent the works of a great modern classical composer.

The tradition of open-air secondhand and antiquarian bookselling in Paris dates back to the Renaissance.

A lone cannonball remains lodged in the walls of the Hotel de Sens as a sober reminder of a revolution.

A museum dedicated to one of Paris’s most famous residents, tucked into a corner of one of the city’s most famous squares.

Dedicated to the art of hunting, with juxtapositions of contemporary art.